77981507639 has 8 divisors (see below), whose sum is σ = 89215840128. Its totient is φ = 66770704440.

The previous prime is 77981507609. The next prime is 77981507641. The reversal of 77981507639 is 93670518977.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77981507639 - 2¹⁶ = 77981442103 is a prime.

It is a super-2 number, since 2×77981507639² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77981507609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5875217 + ... + 5888474.

It is an arithmetic number, because the mean of its divisors is an integer number (11151980016).

Almost surely, 2^77981507639 is an apocalyptic number.

77981507639 is a deficient number, since it is larger than the sum of its proper divisors (11234332489).

77981507639 is a wasteful number, since it uses less digits than its factorization.

77981507639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11764645.

The product of its (nonzero) digits is 20003760, while the sum is 62.

The spelling of 77981507639 in words is "seventy-seven billion, nine hundred eighty-one million, five hundred seven thousand, six hundred thirty-nine".